A number of antibiotics in the prior art belonging to the elfamycin family have been isolated from microorganisms belonging to the genus Streptomyces. The elfamycin family includes mocimycin (kirromycin), 5,6 dihydromocimycin, efrotomycin, aurodox, henicomycin, kirrothricin, factumycin, azdimycin and L-681,217. These antibiotics exhibit activity against gram-positive bacteria.
Other antibiotics derived from Streptomyces species include compounds LL-E19020 alpha and beta, obtained from a subspecies of S. lydicus. These compounds are disclosed in U.S. Pat. No. 4,705,688, issued to Carter et al., and are reported to have antibacterial and growth promotant properties. Although no structural formulae are given for LL-E19020 alpha and beta, it is believed that these compounds are identical to phenelfamycins E and F, described herein.
The present invention encompasses the novel antibiotic agents phenelfamycins A-D and unphenelfamycin. These agents, and the related compounds phenelfamycins E and F, have the following structures: ##STR1##
The phenelfamycins A-F and unphenelfamycin are produced by submerged aerobic fermentation of the microorganisms Streptomyces sp. AB-999F-80 and Streptomyces sp. AB-1047T-33. The compounds described exhibit antibiotic activity against a number of gram-positive and gram-negative anaerobic bacteria including strains of Bacteroides fragilis, Veillonella parvula, Clostridium perfringens, C. difficile, and Propionibacterium acnes. The antibiotics may be recovered from the fermentation broths of Streptomyces sp. AB-999F-80 and Streptomyces sp. AB-1047T-33 by ethyl acetate extraction and from the mycelium by acetone steep.